Purpureocillium lilacinum

Synonymy: 
Paecilomyces lilacinus

Purpureocillium lilacinum is commonly isolated from soil, decaying vegetation, insects, nematodes and as a laboratory contaminant. It is also a causative agent of infection in human and other vertebrates (Luangsa-ard et al. 2011).

RG-1 organism.

Purpureocillium culture

Purpureocillium lilacinum culture.

Morphological description: 
Colonies are fast growing, suede-like to floccose, vinaceous to violet-coloured. Conidiophores are erect 400-600 µm in length, bearing branches with densely clustered phialides. Conidiophore stipes are 3-4 µm wide, yellow to purple and rough-walled. Phialides are swollen at their bases, gradually tapering into a slender neck. Conidia are ellipsoidal to fusiform, smooth-walled to slightly roughened, hyaline to purple in mass, 2.5-3.0 x 2-2.2 µm, and are produced in divergent chains. Chlamydospores are absent. Growth at 38C.

Purpureocillium lilacinum microscopy

Purpureocillium lilacinum conidiophores, phialides and conidia. Note: Rough-walled conidiophore.

Molecular identification: 
ITS sequencing is recommended (Atkins et al. 2005, Luangsa-ard et al. 2011).

Key features: 
Colony pigmentation, phialides with swollen bases, pigmented and rough-walled conidiophore stipes, absence of chlamydospores and growth at 37C. Note: Paecilomyces marquandii differs by having a yellow reverse pigment, smooth conidiophore stipes, presence of chlamydospores, and no growth at 37C.

References: 
Samson (1974), Domsch et al. (1980), McGinnis (1980), Onions et al. (1981), Rippon (1988), de Hoog et al. (2000, 2015), Perdomo et al. (2013).

Antifungal susceptibility: Purpureocillium lilacinum (Australian national data); MIC µg/mL.
  No ≤0.03 0.06 0.125 0.25 0.5 1 2 4 8
AmB 97     1   1   6 8 81
ISAV 1       1          
VORI 95   8 45 34 5     2 1
POSA 82   2 8 11 50 10 1    
ITRA 98 1     6 21 42 5 8 15

 

Back to Hyphomycetes